1. Technical Field
The present invention relates generally to probes, and more particularly, to an elastic seal for use with a sanitary probe for probing a substance.
2. Related Art
Historically, one of the preferred ways to monitor the amount, temperature, pressure or viscosity of a substance, particularly that of a liquid, in a closed container is with the use of a probe assembly. Most probe assemblies are long and thin and have at least one probing member that is designed to send a signal, such as an electrical charge when contacted by a liquid. The probing member is often made of stainless steel or other corrosion resistant electrical conductor. Probe assemblies are also often coated with an adhesion resistant coating member that includes a substance such as polytetrafluoroethylene, known under one brand as Teflon™. This coating member allows the probe assembly to remain sanitary due to its easy cleanability.
One shortcoming in the art has been a tendency of the probing member and the coating member to separate, forming a void between the two. This may be caused by the extreme difficulty in forming a perfect seal between the substances in the probing member and the coating member during manufacture. Further separation of the two may be caused by distinctively different coefficients of thermal expansion (CTE) of the materials used for the probing member and the coating member, for example those of stainless steel and polytetrafluorethylene. As a result, one of the materials expands or contracts more quickly than the other in the case of a change in temperature, causing the two to separate. The substance may enter the void caused by this separation, especially if the probe assembly is used in a high pressure application, and cause the probe to lose sanitary status or cross contaminate a later substance into which the probe assembly is inserted.
In view of the foregoing, there is a need in the art for a sanitary probe that lessens the likelihood the electrode and coating will separate to form a void.